# HG changeset patch
# User Ideenmodellierer
# Date 1685908766 -7200
# Node ID aeb72882f30a2a9716dd586747eadd72c2a54c03
# Parent  19ab6f3ed52aeea85ab52746fa410b90ce21b9ff
Dev Bugfx Empty buffer indication and stability improvments:
The mux prototype used ASCII coding for channel selection while the current realization used real number (0...4) for addressing the mux. The UART read function uses the '0' to indicate an empty buffer element. The mux now loops back '0' used by channel selection causing the read function to process the data. As result data interrups are visible at the display. To avoid this another character has been defined indicate empty buffer locations.
Beside this the functionality has been improved with regard to access speed and better recovery in case of transition failure.

diff -r 19ab6f3ed52a -r aeb72882f30a Small_CPU/Src/uart.c
--- a/Small_CPU/Src/uart.c	Sun Jun 04 21:54:24 2023 +0200
+++ b/Small_CPU/Src/uart.c	Sun Jun 04 21:59:26 2023 +0200
@@ -26,6 +26,9 @@
 
 /* Private variables ---------------------------------------------------------*/
 
+#define BUFFER_NODATA			(7u)		/* The read function needs a byte which indecated that no data for processing is available.*/
+											/* This byte shall never appear in a normal data steam */
+
 #define CHUNK_SIZE				(25u)		/* the DMA will handle chunk size transfers */
 #define CHUNKS_PER_BUFFER		(5u)
 #define COMMAND_TX_DELAY		(30u)		/* The time the sensor needs to recover from a invalid command request */
@@ -83,7 +86,7 @@
 
   MX_USART1_DMA_Init();
 
-  memset(rxBuffer,0,sizeof(rxBuffer));
+  memset(rxBuffer,BUFFER_NODATA,sizeof(rxBuffer));
   rxReadIndex = 0;
   lastCmdIndex = 0;
   rxWriteIndex = 0;
@@ -515,21 +518,22 @@
 	{
 		if(Comstatus_O2 == UART_O2_INIT)
 		{
-			memset((char*)&rxBuffer[rxWriteIndex],(int)0,CHUNK_SIZE);
+			memset((char*)&rxBuffer[rxWriteIndex],(int)BUFFER_NODATA, sizeof(rxBuffer));
 			memset((char*) &tmpSensorDataDiveO2, 0, sizeof(tmpSensorDataDiveO2));
-			externalInterface_SetSensorData(0,(uint8_t*)&tmpSensorDataDiveO2);
+			externalInterface_SetSensorData(0xFF,(uint8_t*)&tmpSensorDataDiveO2);
 
 			lastAlive = 0;
 			curAlive = 0;
 
 			Comstatus_O2 = UART_O2_CHECK;
+			lastComState = UART_O2_IDLE;
 			DigitalO2_SetupCmd(Comstatus_O2,cmdString,&cmdLength);
-			DigitalO2_SelectSensor(activeSensor);
+
 			if(activeSensor < MAX_MUX_CHANNEL)
 			{
-				externalInterface_GetSensorData(activeSensor + 1, (uint8_t*)&tmpSensorDataDiveO2);
+				externalInterface_GetSensorData(activeSensor, (uint8_t*)&tmpSensorDataDiveO2);
 			}
-			delayStartTick = tick;
+
 			tickToTX = COMMAND_TX_DELAY;
 
 			rxState = O2RX_CONFIRM;
@@ -537,7 +541,6 @@
 			errorReadIndex = 0;
 			respondErrorDetected = 0;
 			digO2Connected = 0;
-			lastO2ReqTick = tick;
 			switchChannel = 1;
 
 			requestIntervall = 0;
@@ -557,9 +560,11 @@
 				requestIntervall = REQUEST_INT_SENSOR_MS;
 			}
 			UART_StartDMA_Receiption();
+			lastO2ReqTick = tick + requestIntervall + 1;
 		}
 		if(time_elapsed_ms(lastO2ReqTick,tick) > requestIntervall)		/* repeat request or iterate to next sensor */
 		{
+			respondErrorDetected = 0;
 			lastO2ReqTick = tick;
 			index = activeSensor;
 			if((lastComState == Comstatus_O2) && (Comstatus_O2 != UART_O2_IDLE))
@@ -583,7 +588,6 @@
 				retryRequest = 1;
 				if(pmap[EXT_INTERFACE_SENSOR_CNT-1] == SENSOR_MUX) /* select next sensor if mux is connected */
 				{
-					switchChannel = 0;
 					if(activeSensor < MAX_MUX_CHANNEL)
 					{
 						do
@@ -600,57 +604,62 @@
 								break;
 							}
 						} while(index != activeSensor);
+						externalInterface_GetSensorData(activeSensor, (uint8_t*)&tmpSensorDataDiveO2);
 					}
 				}
-				Comstatus_O2 = UART_O2_REQ_RAW;
-				rxState = O2RX_CONFIRM;
+				if((activeSensor != MAX_MUX_CHANNEL) && (tmpSensorDataDiveO2.sensorId == 0))
+				{
+					Comstatus_O2 = UART_O2_REQ_ID;
+				}
+				else
+				{
+					Comstatus_O2 = UART_O2_REQ_RAW;
+				}
 			}
+			rxState = O2RX_CONFIRM;
 			if(switchChannel)
 			{
 				switchChannel = 0;
 				delayStartTick = tick;
 				DigitalO2_SelectSensor(activeSensor);
-				externalInterface_GetSensorData(activeSensor + 1, (uint8_t*)&tmpSensorDataDiveO2);
 				tickToTX = COMMAND_TX_DELAY;
-				if(tmpSensorDataDiveO2.sensorId == 0)
-				{
-					Comstatus_O2 = UART_O2_REQ_ID;
-				}
 			}
 			else
 			{
+				tickToTX = 0;
 				HAL_UART_Transmit(&huart1,cmdString,cmdLength,10);
 			}
 			DigitalO2_SetupCmd(Comstatus_O2,cmdString,&cmdLength);
 		}
-
-		while((rxBuffer[localRX]!=0))
+	}
+	while((rxBuffer[localRX] != BUFFER_NODATA))
+	{
+		lastReceiveTick = tick;
+		switch(rxState)
 		{
-			lastReceiveTick = tick;
-			switch(rxState)
-			{
-				case O2RX_CONFIRM:	if(rxBuffer[localRX] == '#')
+			case O2RX_CONFIRM:	if(rxBuffer[localRX] == '#')
+								{
+									cmdReadIndex = 0;
+									errorReadIndex = 0;
+								}
+								if(errorReadIndex < sizeof(errorStr)-1)
+								{
+									if(rxBuffer[localRX] == errorStr[errorReadIndex])
 									{
-										cmdReadIndex = 0;
-										errorReadIndex = 0;
-									}
-									if(errorReadIndex < sizeof(errorStr)-1)
-									{
-										if(rxBuffer[localRX] == errorStr[errorReadIndex])
-										{
-											errorReadIndex++;
-										}
-										else
-										{
-											errorReadIndex = 0;
-										}
+										errorReadIndex++;
 									}
 									else
 									{
-										respondErrorDetected = 1;
+										errorReadIndex = 0;
 									}
-									if(rxBuffer[localRX] == cmdString[cmdReadIndex])
-									{
+								}
+								else
+								{
+									respondErrorDetected = 1;
+									errorReadIndex = 0;
+								}
+								if(rxBuffer[localRX] == cmdString[cmdReadIndex])
+								{
 									cmdReadIndex++;
 									if(cmdReadIndex == cmdLength - 1)
 									{
@@ -674,9 +683,11 @@
 										}
 										tmpRxIdx = 0;
 										memset((char*) tmpRxBuf, 0, sizeof(tmpRxBuf));
+										cmdReadIndex = 0;
 										switch (Comstatus_O2)
 										{
 												case UART_O2_CHECK:	Comstatus_O2 = UART_O2_IDLE;
+																	rxState = O2RX_IDLE;
 													break;
 												case UART_O2_REQ_ID: rxState = O2RX_GETNR;
 													break;
@@ -691,6 +702,10 @@
 										}
 									}
 								}
+								else
+								{
+									cmdReadIndex = 0;
+								}
 					break;
 
 				case O2RX_GETSTATUS:
@@ -763,7 +778,7 @@
 										switch (rxState)
 										{
 											case O2RX_GETSTATUS:		StringToInt(tmpRxBuf,&tmpSensorDataDiveO2.status);
-																		externalInterface_SetSensorData(activeSensor+1,(uint8_t*)&tmpSensorDataDiveO2);
+																		externalInterface_SetSensorData(activeSensor,(uint8_t*)&tmpSensorDataDiveO2);
 																		Comstatus_O2 = UART_O2_IDLE;
 																		rxState = O2RX_IDLE;
 													break;
@@ -772,12 +787,12 @@
 																		rxState = O2RX_IDLE;
 													break;
 											case O2RX_HUMIDITY:			StringToInt(tmpRxBuf,(uint32_t*)&tmpSensorDataDiveO2.humidity);				/* raw data cycle */
-																		externalInterface_SetSensorData(activeSensor+1,(uint8_t*)&tmpSensorDataDiveO2);
+																		externalInterface_SetSensorData(activeSensor,(uint8_t*)&tmpSensorDataDiveO2);
 																		Comstatus_O2 = UART_O2_IDLE;
 																		rxState = O2RX_IDLE;
 													break;
 											case  O2RX_GETNR: 			StringToUInt64((char*)tmpRxBuf,&tmpSensorDataDiveO2.sensorId);
-																		externalInterface_SetSensorData(activeSensor+1,(uint8_t*)&tmpSensorDataDiveO2);
+																		externalInterface_SetSensorData(activeSensor,(uint8_t*)&tmpSensorDataDiveO2);
 																		index = activeSensor;
 																		Comstatus_O2 = UART_O2_IDLE;
 																		rxState = O2RX_IDLE;
@@ -791,36 +806,35 @@
 				default:				rxState = O2RX_IDLE;
 					break;
 
-			}
-			rxBuffer[localRX] = 0;
-			localRX++;
-			rxReadIndex++;
-			if(rxReadIndex >= CHUNK_SIZE * CHUNKS_PER_BUFFER)
+		}
+		rxBuffer[localRX] = BUFFER_NODATA;
+		localRX++;
+		rxReadIndex++;
+		if(rxReadIndex >= CHUNK_SIZE * CHUNKS_PER_BUFFER)
+		{
+			localRX = 0;
+			rxReadIndex = 0;
+		}
+	}
+
+	if((digO2Connected) && time_elapsed_ms(lastReceiveTick,HAL_GetTick()) > 4000)	/* check for communication timeout */
+	{
+		digO2Connected = 0;
+		if(curAlive == lastAlive)
+		{
+			for(index = 0; index < MAX_ADC_CHANNEL; index++)
 			{
-				localRX = 0;
-				rxReadIndex = 0;
+				if(pmap[index] == SENSOR_DIGO2)
+				{
+					setExternalInterfaceChannel(index,0.0);
+				}
 			}
 		}
-
-		if((digO2Connected) && time_elapsed_ms(lastReceiveTick,HAL_GetTick()) > 4000)	/* check for communication timeout */
-		{
-			digO2Connected = 0;
-			if(curAlive == lastAlive)
-			{
-				for(index = 0; index < MAX_ADC_CHANNEL; index++)
-				{
-					if(pmap[index] == SENSOR_DIGO2)
-					{
-						setExternalInterfaceChannel(index,0.0);
-					}
-				}
-			}
-			lastAlive = curAlive;
-		}
-		if((dmaActive == 0)	&& (externalInterface_isEnabledPower33()))	/* Should never happen in normal operation => restart in case of communication error */
-		{
-			UART_StartDMA_Receiption();
-		}
+		lastAlive = curAlive;
+	}
+	if((dmaActive == 0)	&& (externalInterface_isEnabledPower33()))	/* Should never happen in normal operation => restart in case of communication error */
+	{
+		UART_StartDMA_Receiption();
 	}
 }
 
@@ -862,11 +876,10 @@
     	{
     		rxWriteIndex = 0;
     	}
-    	if((rxWriteIndex / CHUNK_SIZE) != (rxReadIndex / CHUNK_SIZE))	/* start next transfer if we did not catch up with read index */
+    	if((rxWriteIndex / CHUNK_SIZE) != (rxReadIndex / CHUNK_SIZE) || (rxWriteIndex == rxReadIndex))	/* start next transfer if we did not catch up with read index */
     	{
-    		if(externalInterface_isEnabledPower33())
+    		if(externalInterface_GetUARTProtocol() != 0)
     		{
-    			memset((char*)&rxBuffer[rxWriteIndex],(int)0,CHUNK_SIZE);
 				UART_StartDMA_Receiption();
     		}
     	}